Stator core magnetic characteristic measurement device, stator core magnetic characteristic measurement method, and stator tooth iron loss measurement method

Abstract

To measure the magnetic characteristics of a stator core or teeth without being affected by stress.SOLUTION: In a stator core magnetic characteristic measurement device (1) that measures the magnetic characteristics (the relationship between magnetic flux density and iron loss) of a stator core (2) in which multiple teeth (5) are formed on the inner side of a ring-shaped back yoke (4) of the stator core (2), an excitation interpolation core (3) is arranged between a pair of teeth (5, 5) among the multiple teeth (5) formed inside the stator core (2) in a non-contact state where a gap is provided between an interpolation yoke (6) wound with a first excitation coil (7) and a first measurement coil (8) of the excitation interpolation core (3) and the teeth (5), and the magnetic characteristics of the stator core (2) are measured based on the magnetic field strength of the first excitation coil (7) and the magnetic flux density of the first measurement coil (8) by energizing the first excitation coil (7).SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a stator core magnetic characteristic measuring device and a stator core magnetic characteristic measuring method that measure the magnetic characteristics (relationship between magnetic flux density and iron loss) of a stator core having multiple teeth formed inside the annular back yoke of the stator core, and a stator teeth iron loss measuring method that measures the iron loss of the teeth. [Background technology]

[0002] Rotating electric machines such as electric motors and generators are composed of a rotor and a stator. The stator is configured by winding a stator coil around a stator core. The stator core has a plurality of teeth protruding radially inward from the inside of an annular back yoke.

[0003] In this rotating electric machine, in order to improve the efficiency of the rotating electric machine, it is important to evaluate the magnetic characteristics of the manufactured stator core (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2023-84822 A Summary of the Invention [Problem to be solved by the invention]

[0005] When measuring the magnetic characteristics of a stator core, the magnetic characteristics of the stator core may change significantly due to the influence of stress depending on the material of the stator core.

[0006] Therefore, when measuring the magnetic characteristics of a stator core by pressing an insert yoke for measurement against the teeth formed inside the annular back yoke of the stator core as in the conventional method, it was difficult to accurately measure the magnetic characteristics of the stator core due to the influence of the stress that the teeth receive from the insert yoke. [Means for solving the problem]

[0007] Therefore, in the present invention according to claim 1, in a stator core magnetic property measuring device that measures the magnetic properties (relationship between magnetic flux density and iron loss) of a stator core having a plurality of teeth formed inside the annular back yoke of the stator core, an excitation insert core is arranged between a pair of teeth among the plurality of teeth formed inside the stator core, in a non-contact state with a gap provided between the teeth and the insert yoke around which a first excitation coil and a first measurement coil of the excitation insert core are wound, and the first excitation coil is excited to measure the magnetic properties of the stator core from the magnetic field strength of the first excitation coil and the magnetic flux density of the first measurement coil.

[0008] In addition, in the present invention according to claim 2, in a stator core magnetic characteristic measuring method for measuring the magnetic characteristics (relationship between magnetic flux density and iron loss) of a stator core having a plurality of teeth formed inside an annular back yoke of the stator core, an excitation insert core is arranged between a pair of teeth among the plurality of teeth formed inside the stator core, in a non-contact state with a gap provided between the teeth and an insert yoke around which a first excitation coil and a first measurement coil of the excitation insert core are wound, and the magnetic characteristics of the stator core are measured from the magnetic field strength of the first excitation coil and the magnetic flux density of the first measurement coil by exciting the first excitation coil.

[0009] According to a third aspect of the present invention, in a stator teeth iron loss measuring method for measuring iron loss of teeth formed inside an annular back yoke of a stator core, a stator core magnetic characteristic measuring device according to the first aspect of the invention is used to excite a first excitation coil and measure the magnetic characteristics of the stator core from the magnetic field strength of the first excitation coil and the magnetic flux density of the first measurement coil, an inner yoke is used to wind a second excitation coil and a second measurement coil around the inner yoke, the second excitation coil is excited and the magnetic characteristics of the inner yoke are measured from the magnetic field strength of the second excitation coil and the magnetic flux density of the second measurement coil, a stator core is used to wind a third excitation coil and a third measurement coil around the back yoke, and the third excitation coil is wound around the inner yoke. The third excitation coil is excited to measure the magnetic characteristics of the back yoke from the magnetic field strength of the third excitation coil and the magnetic flux density of the third measurement coil, the iron loss of the interpolation yoke is calculated from the magnetic flux density at the position where the first measurement coil is wound around the interpolation yoke based on the magnetic characteristics of the interpolation yoke measured using the interpolation yoke, the iron loss of the back yoke is calculated from the magnetic flux density of the back yoke based on the magnetic characteristics of the back yoke measured using the stator core, the iron loss of the stator core is calculated from the magnetic flux density of the stator core based on the magnetic characteristics of the stator core measured using the stator core magnetic characteristic measuring device of claim 1, and the iron loss of the teeth is calculated by subtracting the iron loss of the interpolation yoke and the iron loss of the back yoke from the iron loss of the stator core. Effect of the Invention

[0010] In the present invention, the magnetic characteristics of the stator core are measured in a non-contact state with a gap provided between the teeth and the inserted yoke, so that the magnetic characteristics of the stator core can be measured without being affected by stress.

[0011] Furthermore, the iron loss of the teeth can be measured satisfactorily based on the magnetic characteristics of the stator core measured without being affected by stress. [Brief description of the drawings]

[0012] [Figure 1] FIG. 2 is an explanatory diagram showing a stator core magnetic characteristic measuring device. [Diagram 2] FIG. [Diagram 3] FIG. 4 is an explanatory diagram showing a method for measuring the magnetic characteristics of the insertion yoke. [Figure 4] FIG. 4 is an explanatory diagram showing a method for measuring the magnetic characteristics of the back yoke. [Diagram 5] Graphs showing the measurement results of magnetic properties ((a) stator core, (b) inner yoke, (c) back yoke). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific configurations of a stator core magnetic characteristic measuring device, a stator core magnetic characteristic measuring method, and a stator teeth iron loss measuring method according to the present invention will be described with reference to the drawings.

[0014] As shown in Figs. 1 and 2, in a stator core magnetic characteristic measuring device 1, an exciting insertion core 3 is inserted into the inner hollow portion of a stator core 2 serving as an object to be measured.

[0015] The stator core 2 has a plurality of teeth (stator teeth) 5 that protrude radially inward and are formed at equal intervals in the circumferential direction on the inner peripheral surface of the annular back yoke 4. Note that, although the back yoke 4 of the stator core 2 is formed in an annular shape here, it is not limited thereto and may be formed in an annular shape such as a rectangular annular shape.

[0016] The exciting core 3 has a first exciting coil 7 wound around the central outer periphery of a straight rod-shaped inserting yoke 6 and a first measurement coil 8 wound around the outer periphery of one end (tip) of the inserting yoke 6 .

[0017] The first excitation coil 7 is connected to the controller 9 via a D / A converter 10, a power amplifier 11, and a shunt resistor 12. This allows the controller 9 to excite the first excitation coil 7 with an excitation voltage of a predetermined waveform. Note that a first measurement coil 8 is provided in the inner yoke 6 to feedback control the controller 9, so that the waveform of the magnetic flux density inside the excitation inner core 3 becomes a sine wave with a form factor of 1.11±0.1.

[0018] Further, the shunt resistor 12 connected to the first exciting coil 7 is connected to the controller 9 via a preamplifier 13 and an A / D converter 14. This allows the controller 9 to measure the strength of the magnetic field of the first exciting coil 7 from the exciting current A passed through the first exciting coil 7.

[0019] The first measuring coil 8 is connected to a controller 9 via a preamplifier 15 and an A / D converter 14. This allows the controller 9 to measure the magnetic flux density from the induced voltage of the first measuring coil 8.

[0020] In the stator core magnetic characteristic measuring device 1, the excitation insert core 3 is disposed between a pair of teeth 5, 5 of the multiple teeth 5 formed inside the stator core 2, in a non-contact state with a certain gap provided between both ends of the insert yoke 6 around which the first excitation coil 7 and the first measurement coil 8 of the excitation insert core 3 are wound, and the tips of the teeth 5, 5. Note that the teeth 5 into which the excitation insert core 3 (insertion yoke 6) is inserted are not limited to two opposing teeth 5, 5, and may be a pair of multiple teeth 5.

[0021] In the above-mentioned stator core magnetic property measuring device 1, the first excitation coil 7 is variably excited by the controller 9, and the relationship between the magnetic field strength obtained from the first excitation coil 7 and the magnetic flux density of the first measuring coil 8 (the magnetic property of the stator core 2) is measured.

[0022] This stator core magnetic characteristic measuring device 1 can create a virtual analysis model by modeling on a computer using physical properties such as the shapes and materials of the stator core 2 (back yoke 4 and teeth 5) and the insert yoke 6.

[0023] For an analytical model created on a computer, electromagnetic field analysis can be performed using known electromagnetic field analysis software (for example, JMAG (made by JSOL Corporation)).

[0024] By performing electromagnetic field analysis on the analytical model, it is possible to determine the magnetic flux density at the position where the first measurement coil 8 is wound around the interpolation yoke 6, the magnetic flux density at the back yoke 4 of the stator core 2, and the magnetic flux density throughout the stator core 2.

[0025] Moreover, by performing an electromagnetic field analysis on the analytical model, it is possible to obtain the magnetic flux density at one end of the inserting yoke 6 and the tip of the tooth 5. By creating analytical models with different gaps between one end of the inserting yoke 6 and the tip of the tooth 5 and performing an electromagnetic field analysis on each analytical model to obtain the magnetic flux density at one end of the inserting yoke 6 and the tip of the tooth 5, it is possible to understand the correlation between the magnetic flux density at one end of the inserting yoke 6 and the magnetic flux density at the tip of the tooth 5 facing the one end of the inserting yoke 6 across the gap and the gap, and it is possible to grasp the range where there is no effect due to the gap (for example, the magnetic flux density difference is less than a predetermined value), and to set the gap so as to be within that range.

[0026] By using the above-mentioned stator core magnetic property measuring device 1 in which a gap is set between one end of the inserted yoke 6 and the tips of the teeth 5 in this manner, it is possible to measure the magnetic properties of the entire stator core 2 (a graph showing the relationship between magnetic flux density and iron loss), as shown in Figure 5(a).

[0027] On the other hand, the magnetic flux density of the stator core 2 can be measured by actual measurement. In particular, since the stator core 2 is used as a motor, the magnetic flux density near the operating point of the motor, which is converted into data, can be measured multiple times to obtain the iron loss at each operating point. Note that the magnetic flux density of the entire stator core 2 can also be obtained by performing an electromagnetic field analysis on an analysis model in which a gap is set between one end of the insertion yoke 6 and the tip of the teeth 5 as described above.

[0028] Then, the iron loss of the entire stator core 2 can be obtained from the magnetic flux density in the entire stator core 2 based on the magnetic characteristics of the entire stator core 2 obtained by measurement by the stator core magnetic characteristic measuring device 1.

[0029] In addition, the magnetic characteristics (graph showing the relationship between magnetic flux density and iron loss) of the inner yoke 6 can be measured by using a known measuring device that complies with JIS C2556 "Testing method for magnetic characteristics of single sheet electromagnetic steel".

[0030] Here, the first excitation coil 7 and the first measurement coil 8 in the stator core magnetic characteristic measuring device 1 are replaced with a second excitation coil 16 and a second measurement coil 17, and as shown in Fig. 3, the second excitation coil 16 and the second measurement coil 17 are wound around the outer periphery of the inner yoke 6, and both ends of the inner yoke 6 are clamped by yokes 18 and 19. The second excitation coil 16 is variably excited by the controller 9, and the relationship between the strength of the magnetic field obtained from the second excitation coil 16 and the magnetic flux density of the second measurement coil 17 (magnetic characteristic of the inner yoke 6) is measured. The second excitation coil 16 and the second measurement coil 17 may be the same as the first excitation coil 7 and the first measurement coil 8 and used in the same positions.

[0031] This allows the magnetic characteristics (a graph showing the relationship between magnetic flux density and iron loss) of the inner yoke 6 to be measured, as shown in FIG. 5(b).

[0032] On the other hand, the magnetic flux density of the inserted yoke 6 can be measured by actual measurement. The magnetic flux density of the inserted yoke 6 can be measured by using the first measurement coil 8 of the stator core magnetic characteristic measuring device 1. Note that, by performing an electromagnetic field analysis on an analysis model in which a gap is set between one end of the inserted yoke 6 and the tip of the tooth 5 as described above, the magnetic flux density at the position where the first measurement coil 8 of the inserted yoke 6 is wound can also be obtained.

[0033] Then, based on the magnetic characteristics of the inserting yoke 6 obtained by measurement with a measuring device, the iron loss of the inserting yoke 6 can be obtained from the magnetic flux density at the position where the first measuring coil 8 of the inserting yoke 6 is wound.

[0034] As for the back yoke 4, the first excitation coil 7 and the first measurement coil 8 in the stator core magnetic characteristic measuring device 1 are replaced with a third excitation coil 20 and a third measurement coil 21, and as shown in Fig. 4, the third excitation coil 20 is evenly wound around the entire circumference of the back yoke 4 around the outer periphery of the entire stator core 2, and the third measurement coil 21 is wound only around the back yoke 4 between the two teeth 5. The third excitation coil 20 is variably excited by the controller 9, and the relationship between the strength of the magnetic field obtained from the third excitation coil 20 and the magnetic flux density of the third measurement coil 21 (magnetic characteristic of the back yoke 4) is measured. Note that the teeth 5 formed on the stator core 2 are formed to protrude unilaterally from the inner circumference of the back yoke 4 toward the radial inside and do not form a magnetically closed circuit, so that the magnetic characteristic of the back yoke 4 can be measured without being affected by the teeth 5 even with the above measurement method.

[0035] This makes it possible to measure the magnetic properties (graph showing the relationship between magnetic flux density and iron loss) of the back yoke 4 of the stator core 2, as shown in FIG. 5(c).

[0036] On the other hand, the magnetic flux density of the back yoke 4 can be measured by actual measurement. The magnetic flux density of the back yoke 4 can be measured by connecting a third measurement coil 21 to the A / D converter 14 of the stator core magnetic characteristic measuring device 1 via a preamplifier 22 as shown in Figures 1 and 2. The magnetic flux density in the back yoke 4 can also be found by performing an electromagnetic field analysis on an analysis model in which a gap is set between one end of the insertion yoke 6 and the tip of the teeth 5 as described above.

[0037] Then, the iron loss of the back yoke 4 can be obtained from the magnetic characteristics of the back yoke 4 obtained by measurement with the measuring device and the magnetic flux density in the back yoke 4 obtained by analysis of the analytical model.

[0038] In this way, the iron loss of the stator core 2, the iron loss of the inserted yoke 6, and the iron loss of the back yoke 4 can be determined, and the iron loss of the teeth 5 can be determined by subtracting the iron loss of the inserted yoke 6 and the iron loss of the back yoke 4 from the iron loss of the stator core 2.

[0039] As described above, in the stator core magnetic property measuring device 1 and the stator core magnetic property measuring method using the device 1, the excitation insert core 3 is arranged between a pair of teeth 5, 5 of the multiple teeth 5 formed inside the stator core 2, in a non-contact state with a gap provided between the teeth 5 and the insert yoke 6 around which the first excitation coil 7 and first measurement coil 8 of the excitation insert core 3 are wound, and the first excitation coil 7 is excited to measure the magnetic properties of the stator core 2 from the magnetic field strength of the first excitation coil 7 and the magnetic flux density of the first measurement coil 8.

[0040] In this way, in the stator core magnetic property measuring device 1 and stator core magnetic property measuring method configured as described above, the magnetic properties of the stator core 2 are measured in a non-contact state with a gap provided between the teeth 5 and the inserted yoke 6, so that the magnetic properties of the stator core 2 can be measured without being affected by stress.

[0041] Further, using the above-mentioned stator core magnetic characteristic measuring device 1, the first excitation coil 7 is excited to measure the magnetic characteristics of the stator core 2 from the magnetic field strength of the first excitation coil 7 and the magnetic flux density of the first measurement coil 8, the second excitation coil 16 and the second measurement coil 17 are wound around the inner yoke 6 using the inner yoke 6, the second excitation coil 16 is excited to measure the magnetic characteristics of the inner yoke 6 from the magnetic field strength of the second excitation coil 16 and the magnetic flux density of the second measurement coil 17, and the third excitation coil 20 and the third measurement coil 21 are wound around the back yoke 4 using the stator core 2, the third excitation coil 20 is excited to measure the magnetic field strength of the third excitation coil 20 and the magnetic flux density of the third measurement coil 21. The magnetic characteristics of the back yoke 4 are measured from the magnetic flux density, the iron loss of the interpolation yoke 6 is calculated from the magnetic flux density at the position where the first measurement coil 8 of the interpolation yoke 6 is wound based on the magnetic characteristics of the interpolation yoke 6 measured using the interpolation yoke 6, the iron loss of the back yoke 4 is calculated from the magnetic flux density of the back yoke 4 based on the magnetic characteristics of the back yoke 4 measured using the stator core 2, the iron loss of the stator core 2 is calculated from the magnetic flux density of the stator core 2 based on the magnetic characteristics of the stator core 2 measured using the stator core magnetic characteristic measuring device 1, and the iron loss of the teeth 5 is calculated by subtracting the iron loss of the interpolation yoke 6 and the iron loss of the back yoke 4 from the iron loss of the stator core 2.

[0042] This makes it possible to satisfactorily measure the iron loss of the teeth 5 based on the magnetic characteristics of the stator core 2 measured without being affected by stress.

[0043] In addition, by performing a magnetic field analysis on an analytical model that models the stator core magnetic characteristic measuring device 1, the magnetic flux density at the position where the first measurement coil 8 is wound on the interpolation yoke 6, the magnetic flux density of the back yoke 4, and the magnetic flux density of the stator core 2 are obtained, the first excitation coil 7 is excited using the stator core magnetic characteristic measuring device 1 to measure the magnetic characteristics of the stator core 2 from the magnetic field strength of the first excitation coil 7 and the magnetic flux density of the first measurement coil 8, the second excitation coil 16 and the second measurement coil 17 are wound around the interpolation yoke 6 using the interpolation yoke 6, the second excitation coil 16 is excited to measure the magnetic characteristics of the interpolation yoke 6 from the magnetic field strength of the second excitation coil 16 and the magnetic flux density of the second measurement coil 17, the third excitation coil 20 and the third measurement coil 21 are wound around the back yoke 4 using the stator core 2, and the third excitation coil 20 and the third measurement coil 21 are wound around the back yoke 4 using the stator core 2. The third excitation coil 20 is excited to measure the magnetic characteristics of the back yoke 4 from the magnetic field strength of the third excitation coil 20 and the magnetic flux density of the third measurement coil 21, the iron loss of the interpolation yoke 6 is calculated from the magnetic flux density at the position where the first measurement coil 8 is wound on the interpolation yoke 6 calculated by magnetic field analysis and the magnetic characteristics of the interpolation yoke 6 measured using the interpolation yoke 6, the iron loss of the back yoke 4 is calculated from the magnetic flux density of the back yoke 4 calculated by magnetic field analysis and the magnetic characteristics of the back yoke 4 measured using the stator core 2, the iron loss of the stator core 2 is calculated from the magnetic flux density of the stator core 2 calculated by magnetic field analysis and the magnetic characteristics of the stator core 2 measured using the stator core magnetic characteristic measuring device 1, and the iron loss of the teeth 5 is calculated by subtracting the iron loss of the interpolation yoke 6 and the iron loss of the back yoke 4 from the iron loss of the stator core 2. [Explanation of symbols]

[0044] 1 Stator core magnetic property measuring device 2 Stator core 3 Excitation core 4 Back yoke 5 teeth 6 insert yoke 7 First excitation coil 8 First measurement coil 9 Controller 10 D / A Converter 11 Power amplifier 12 Shunt resistor 13 Preamplifier 14 A / D Converter 15 Preamplifier 16 Second excitation coil 17 Second measuring coil 18,19 Yoke 20 third excitation coil 21 third measurement coil 22 Preamplifier

Claims

1. A stator core magnetic characteristic measuring device measures the magnetic characteristics (relationship between magnetic flux density and iron loss) of a stator core having a plurality of teeth formed inside an annular back yoke of the stator core, an excitation core is disposed between a pair of teeth among a plurality of teeth formed inside a stator core in a non-contact state with a gap provided between an insertion yoke around which a first excitation coil and a first measurement coil of the excitation core are wound and the teeth; A stator core magnetic characteristic measuring device, comprising: an excitation coil for exciting a first excitation coil; and a measurement coil for measuring the magnetic characteristics of the stator core from the magnetic field strength of the first excitation coil and the magnetic flux density of a first measurement coil.

2. A stator core magnetic characteristic measuring method for measuring magnetic characteristics (relationship between magnetic flux density and iron loss) of a stator core having a plurality of teeth formed inside an annular back yoke of the stator core, an excitation core is disposed between a pair of teeth among a plurality of teeth formed inside a stator core in a non-contact state with a gap provided between an insertion yoke around which a first excitation coil and a first measurement coil of the excitation core are wound and the teeth; A method for measuring magnetic characteristics of a stator core, comprising the steps of: exciting a first exciting coil; and measuring the magnetic characteristics of the stator core from the magnetic field strength of the first exciting coil and the magnetic flux density of a first measuring coil.

3. A stator teeth iron loss measuring method for measuring iron loss of teeth formed inside an annular back yoke of a stator core, comprising: Using the stator core magnetic characteristic measuring device according to claim 1, a first exciting coil is excited to measure the magnetic characteristics of the stator core from the magnetic field strength of the first exciting coil and the magnetic flux density of the first measuring coil; using an inserting yoke, winding a second exciting coil and a second measuring coil around the inserting yoke, exciting the second exciting coil to measure a magnetic characteristic of the inserting yoke from a magnetic field strength of the second exciting coil and a magnetic flux density of the second measuring coil; using the stator core, winding a third excitation coil and a third measurement coil around the back yoke, exciting the third excitation coil to measure the magnetic characteristics of the back yoke from the magnetic field strength of the third excitation coil and the magnetic flux density of the third measurement coil; determining an iron loss of the insertion yoke from a magnetic flux density at a position where the first measurement coil is wound around the insertion yoke based on a magnetic characteristic of the insertion yoke measured using the insertion yoke; The iron loss of the back yoke is calculated from the magnetic flux density of the back yoke based on the magnetic characteristics of the back yoke measured using the stator core. determining an iron loss of the stator core from a magnetic flux density of the stator core based on the magnetic characteristics of the stator core measured using the stator core magnetic characteristic measuring device according to claim 1; A stator teeth iron loss measuring method characterized in that the iron loss of the teeth is determined by subtracting the iron loss of the insertion yoke and the iron loss of the back yoke from the iron loss of the stator core.

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